"The hardest Sudoku in the world" that a mathematical expert created over three months

SudokuGenerally, it is difficult as few numbers are filled from the beginning, and the experts seem to understand the difficulty of the problem by just looking at it at first glance. However, it is not disappointing when there is a part which can not be solved by "logical" alone, or when it is found that there are two or more solutions unless "intuition" is used in Sudoku which "it seems that this is likely to occur" Is it? Such Sudoku is not correct as Sudoku.

A Finnish scientist has as many solutions as possible and it is as infinitely difficult as "a correct Sudoku" that can fill all the trouts with "logic" rather than "guess", "the world's hardest Sudoku It seems that they succeeded in producing ".

Details are as below.9 by 9 Sudoku Solver

This is the "world's hardest Sudoku".Ω-3 fatty acidSell ​​supplementsEfamolAt the request of the company, it was created by a Sudoku creation program handed out by Dr. Arto Inkala, a Finnish environmental scientist who has a doctorate in science and applied mathematics.


As in chess and shogi, the number of what to think about anything is increased in Sudoku which can be solved by thinking up to "a few fingers" and "... filled with that number if you insert this number here" The degree of difficulty will be higher.

It is this Sudoku that it took three months to create, but there may be people who can solve it immediately with "guessho". "Some people may wonder why it's so difficult to solve in 15 or 30 minutes depending on the number of 3 or 4 licks, but in order to solve this puzzle with logic alone, It will take a few days, "Dr. Inkala says.

Dr. Inkala who enjoys making puzzles in leisure time. Dr. Inkala himself, who has a doctorate in science and applied mathematics himself, is an expert in mathematics, but "the person who solves the puzzle does not even need to be able to add, logical thinking, attention, persistence become the key to solving Sudoku I will tell you.


The answer isHere. The editorial staff who challenged this Sudoku gave up in 30 minutes, so to create an answer9 by 9 Sudoku Solverusing.